Why is QS Defy a downplayed oil? Is it their terrible sludging reputation from years ago, or company going broke and being sold to Shell, slick 50 fiasco? In the High Mileage Synthetic Blend category this is fairly strong additive package at the price-point. I can't think of any other HM syn/blend oil that includes moly or boron. For a 4-5k change interval, this is good stuff. On paper Valvoline, Castrol seem weaker and less additive filled but are recommended more frequently. I know pouring tons of additives in oil doesn't result in any less wear or benefit in the short term, but what are these other guys thinking?
